When someone suffers a tragic accident or is inflicted with a terrible disease, the ability to effectively communicate or access a computer is frequently lost, especially when the accident or disease causes paralysis or induces, in the opposite extreme, involuntary motion of the body. In either scenario, eye movements are often the only aspect of a person's body that the person can control. As such, users may seek to employ alternative and augmentative communications (AAC) technologies. Some forms of alternative access technologies include eye-tracking systems, head pointing mice, voice activated systems, or scanning technology.
Some alternative access technologies are characterized by certain limitations. For example, scanning technology may sometimes be inefficient because it is not a direct selection technology. Scanning typically works by successively highlighting rows of buttons and then having the user actuate a switch to choose the row for which he/she wishes to push a button. Each button is then highlighted and clicking the switch again selects the button. Voice activated systems are only generally available to people with disabilities who can speak. Head pointing mice only work for those that have good head control, so individuals with paralysis or involuntary motion cannot use it.
In light of the above limitations, eye-tracking technology has emerged as an attractive option for users to interface with electronic devices, such as but not limited to computers, speech generation devices, and other electronic technologies. One example of an eye-tracking access method is disclosed in U.S. Pat. No. 6,152,563 to Hutchinson et al. Such patent generally describes an eye-gaze direction detection system and method that can be used to help detect eye movement or determine eye-gaze direction (i.e., a user's point of regard).
The Hutchinson et al. '563 patent is a robust system, but may be characterized by certain limitations. For example, the eye-tracking technology in the Hutchinson et al. '563 patent requires a fixed head position and/or a user initiated calibration procedure. As such, users with involuntary motion frequently cannot benefit from the technology.
In addition, the zooming technique disclosed in the Hutchinson et al. '563 patent requires zooming to be either on or off. This feature limits the adaptability of the zooming features and requires time and effort on the part of a user who may want to toggle between the different available zooming modes.
Still further, additional features may be desired to enhance the selection system afforded by the technology in the Hutchinson et al. '563 patent, including selection features associated with the user's context, type of feedback mechanism (e.g, pointer) showing where the user is looking, the amount of zooming, size of the focus region, etc.
In light of the various design concerns in the field of eye gaze technologies, a need continues to exist for refinements and improvements to address the above concerns and others. While various implementations of eye gaze technologies and associated features and steps have been developed, no design has emerged that is known to generally encompass all of the desired characteristics hereafter presented in accordance with aspects of the subject technology.